According to one embodiment, a memory system stores a part of a logical-to-physical address translation table stored in a nonvolatile memory, as a first cache, in a random-access memory, and stores a compressed logical-to-physical address translation table obtained by compressing the logical-to-physical address translation table, as a second cache, in the random-access memory. The memory system stores first information indicative of a part of a first address translation data, in a first area of a first entry of the second cache where first compressed address translation data is stored. When executing processing of checking a part of the first address translation data, the memory system refers to the first information stored in the first entry of the second cache.